Passbook printers which can print on notebooks such as passbooks have a built-in page turning apparatus which is a mechanism to automatically turn pages without involvement by the user. Specifically, when entries to a page in printing are finished and entries to the next page are necessary, the printers themselves execute automated page turning without ejecting passbooks.
To execute the automated passbook page turning, a turning mechanism has been used in which a turning roller is first landed on (brought into contact with) a turning target page, that is, the latter of the spread pages of the passbook, and is then rotated to shift the paper by friction, thereby raising the paper between the landed position and the folding axis of the passbook (or the central fold) (this is referred to as buckling). Then, when a sensor or the like senses that the buckling of the paper has reached a predetermined level, the turning roller is further rotated to bounce the paper onto the turning roller, thereby placing it onto the first half of the spread pages.
However, when various types passbooks of different sizes, particularly, different lengths from the folding axis to the opposed side of the spread pages (hereinafter, referred to as “passbook length”) are handled by the same turning mechanism, the turning behavior must be changed from one passbook to another. In other words, for passbook printers for use in countries in which the passbook length has a unified standard, page turning apparatuses can be optimized to the passbook length. However, a significant number of countries use passbooks of different lengths. Conventional passbook printers used in such countries must be optimized to some of the passbook lengths. Therefore, turning of the pages of passbooks of significantly different sizes is prone to cause troubles such as double turning or page folding.
Referring to the accompanying drawings, the conventional technique will be described hereinbelow, wherein like reference numerals designate like or corresponding components throughout.
FIG. 1 shows an example of the mechanism of a page turning apparatus 100 for use in conventional passbook printers. Page turning rollers (also referred to as turning rollers) 102 are fixed to a roller shaft 104 and are retained by arms 106. At the time a passbook is conveyed from the left to the page turning apparatus 100, the arms 106 are held substantially horizontal with pins 110 fixed to an actuating shaft 108, and the turning rollers 102 are retracted upward from the path of the passbook. The passbook is conveyed to a predetermined “passbook holding position” through the path between a bed plate 112 and a guide plate 114. A feed roller 116 that conveys the passbook also serves to fix the passbook to the position during page turning operation by the turning rollers 102.
FIG. 2 shows the page turning apparatus 100 of FIG. 1, as viewed from the side. The procedure of conventional page turning will be described with reference to FIG. 1 and FIGS. 2(a) to 2(e).
A passbook 202 is conveyed to a “passbook holding position”, that is, a position at which the almost center of the latter of the spread pages is directly under the turning rollers 102 (the position at which A=B holds in FIG. 2(a)) (see FIG. 2(a)). The actuating shaft 108 is rotated counterclockwise through an angle by the attraction of an external solenoid (not shown) to tilt the pins 110 at the corresponding angle, thereby removing the restriction of the arms 106, so that the turning rollers 102 are pushed against the surface of the latter of the spread pages by the force of springs 118 (see FIG. 2(b)). The turning rollers 102, which are slowly driven counterclockwise via a belt 120 by the power of an external motor, shift only the uppermost paper 212 of the latter page by friction to “buckle” it in an angular form. At that time, the guide plate 114 made of a lightweight material is raised with a shaft 204 as a pivot (fulcrum) by the swell of the paper 212. The curved surface 206 on the pivot is detected by a reflective sensor 208 (see FIG. 2(c)).
As the detection by the sensor 208 triggers the removal of the attraction of the external solenoid, the actuating shaft 108 returns to the initial position to retract the turning rollers 102 upward. The turning rollers 102 then rotate counterclockwise at high speed for a predetermined time to bounce the angled paper 212 in contact with the surface of the turning rollers 102 above the turning rollers 102 (see FIG. 2(d)). The paper 212, when bounced, becomes substantially flat between the turning rollers 102 and the guide plate 114 (see FIG. 2(e)). Thereafter, as the passbook is conveyed to the left in FIG. 2, the bounced paper 212 is rolled under the turning rollers 102 to be placed on the first half of the spread pages. Thus, the turning operation is completed, and the guide plate 114 returns to the initial horizontal position by gravity (see FIG. 2(a)).
To execute the above-described turning operation to different-length passbooks by the same mechanism, it is desirable that the paper to be buckled be swelled at the same angle, and that the “passbook holding position” be set so that the distance from the passbook folding axis 210 to the position to which the turning rollers 102 land is held constant (that is, B is fixed in FIG. 2(a)). However, for short passbooks, this setting reduces the distance from the lower end of the passbooks to the turning rollers 102 landing position. This causes the lower end of the object paper to pass through the contact point of the turning rollers 102 at the stage of generating the same angled shape, to swell also the next page by the turning rollers 102. As a result, two sheets of paper are bounced above the turning rollers 102 to cause the problem of double turning.
Therefore, passbooks have generally been conveyed with the “passbook holding position” fixed so that the distance from the lower end of the passbook to the turning rollers 102 landing position is fixed (that is, A is fixed in FIG. 2(a)) irrespective of the passbook length. However, with such a “passbook holding position”, the distance from the turning rollers 102 landing position to the folding axis 210 is in turn decreased. This makes the swell of buckled paper distorted and sharp as compared with that of standard-length passbooks to cause unsmooth bouncing, thus increasing troubles such as folds. Such troubles occur more frequently in passbooks made of limp paper (or soft paper).
To address these problems, Japanese Unexamined Patent Application Publication No. 2000-318349 describes an apparatus for turning pages in such a manner as to automatically adjust the position of a passbook in the optimum passbook holding position corresponding to passbook length information obtained by a sensor.
However, under this method, a page turning error or double (or multiple) turning cannot be recognized until page identification information such as printed page numbers is read by an optical page reader (OPR) after completion of the page turning process. In other words, in the event of a page turning error, the apparatus cannot move to a passbook-holding position adjusting process until the turning roller makes one rotation, then the passbook is conveyed to a position at which the page identification information can be read, and the information is read. This is not desirable because it takes much time. In the event of double turning, without a reverse turning mechanism, the passbook must be ejected, and the user must correct the page of the ejected passbook and insert it again, resulting in troublesome time-consuming work. This method is not useful for preventing a turning error or the like which is often caused directly by paper quality (the hardness or coefficient of friction of paper) and the property of the spread pages because it adjusts the passbook holding position in the event of a turning error or the like only with passbook length information.